From 9ad6049736c58cca098b13ed128e7de0940f94a0 Mon Sep 17 00:00:00 2001
From: Huihui Zhang <huihuiz@quicinc.com>
Date: Fri, 18 Sep 2020 11:26:28 -0700
Subject: [PATCH] [InstCombine][SVE] Skip scalable type for
 InstCombiner::getFlippedStrictnessPredicateAndConstant.

We cannot iterate on scalable vector, the number of elements is unknown at compile-time.

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D87918
---
 llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp |  4 ++--
 llvm/test/Transforms/InstCombine/vscale_cmp.ll          | 11 +++++++++++
 2 files changed, 13 insertions(+), 2 deletions(-)
 create mode 100644 llvm/test/Transforms/InstCombine/vscale_cmp.ll

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
index 74e9525..a0b4c221 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
@@ -5260,8 +5260,8 @@ InstCombiner::getFlippedStrictnessPredicateAndConstant(CmpInst::Predicate Pred,
     // Bail out if the constant can't be safely incremented/decremented.
     if (!ConstantIsOk(CI))
       return llvm::None;
-  } else if (auto *VTy = dyn_cast<VectorType>(Type)) {
-    unsigned NumElts = cast<FixedVectorType>(VTy)->getNumElements();
+  } else if (auto *FVTy = dyn_cast<FixedVectorType>(Type)) {
+    unsigned NumElts = FVTy->getNumElements();
     for (unsigned i = 0; i != NumElts; ++i) {
       Constant *Elt = C->getAggregateElement(i);
       if (!Elt)
diff --git a/llvm/test/Transforms/InstCombine/vscale_cmp.ll b/llvm/test/Transforms/InstCombine/vscale_cmp.ll
new file mode 100644
index 0000000..bbceab0
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/vscale_cmp.ll
@@ -0,0 +1,11 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -instcombine -S | FileCheck %s
+
+define <vscale x 2 x i1> @sge(<vscale x 2 x i8> %x) {
+; CHECK-LABEL: @sge(
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sge <vscale x 2 x i8> [[X:%.*]], zeroinitializer
+; CHECK-NEXT:    ret <vscale x 2 x i1> [[CMP]]
+;
+  %cmp = icmp sge <vscale x 2 x i8> %x, zeroinitializer
+  ret <vscale x 2 x i1> %cmp
+}
-- 
2.7.4